To create a locally updating version control system for a text document, you can use a simple script written in a programming language such as Python. Here is a high-level outline of the steps you could follow:
Define the directory where the text document is located and the filename of the document.
Use a function or method in the programming language to read the contents of the text document into memory.
Implement a loop that continuously prompts the user for input and waits for the user to enter a command.
Implement a command to save the current version of the text document by writing the contents of the document back to the file on the filesystem.
Implement a command to update the text document by appending new content entered by the user to the end of the document.
Implement a command to display the current contents of the text document.
Save the script in the same directory as the text document and run the script to initiate the version control system.
Here is some example Python code that implements these steps: